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data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>html标签学习</span><!--]--><!----></a><!----><!--]--><!--]--></div></section></div><div class="group" data-v-a186aa16><section class="VPSidebarGroup collapsible collapsed" data-v-a186aa16 data-v-6e45c352><div class="title" role="button" data-v-6e45c352><h2 class="title-text" data-v-6e45c352>JavaScript教程</h2><div class="action" data-v-6e45c352><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewbox="0 0 24 24" class="icon minus" data-v-6e45c352><path d="M19,2H5C3.3,2,2,3.3,2,5v14c0,1.7,1.3,3,3,3h14c1.7,0,3-1.3,3-3V5C22,3.3,20.7,2,19,2zM20,19c0,0.6-0.4,1-1,1H5c-0.6,0-1-0.4-1-1V5c0-0.6,0.4-1,1-1h14c0.6,0,1,0.4,1,1V19z"></path><path d="M16,11H8c-0.6,0-1,0.4-1,1s0.4,1,1,1h8c0.6,0,1-0.4,1-1S16.6,11,16,11z"></path></svg><svg version="1.1" xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" class="icon plus" data-v-6e45c352><path d="M19,2H5C3.3,2,2,3.3,2,5v14c0,1.7,1.3,3,3,3h14c1.7,0,3-1.3,3-3V5C22,3.3,20.7,2,19,2z M20,19c0,0.6-0.4,1-1,1H5c-0.6,0-1-0.4-1-1V5c0-0.6,0.4-1,1-1h14c0.6,0,1,0.4,1,1V19z"></path><path d="M16,11h-3V8c0-0.6-0.4-1-1-1s-1,0.4-1,1v3H8c-0.6,0-1,0.4-1,1s0.4,1,1,1h3v3c0,0.6,0.4,1,1,1s1-0.4,1-1v-3h3c0.6,0,1-0.4,1-1S16.6,11,16,11z"></path></svg></div></div><div class="items" data-v-6e45c352><!--[--><!--[--><a class="VPLink link link" href="/docs/frontend/js/JavaScript%E7%9A%84%E5%9F%BA%E7%A1%80%E8%AF%AD%E6%B3%95.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>基础语法</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E5%88%86%E6%94%AF%E7%BB%93%E6%9E%84.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>分支结构</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E5%BE%AA%E7%8E%AF%E7%BB%93%E6%9E%84.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>循环结构</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E5%87%BD%E6%95%B0(%E4%B8%8A).html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>函数（上）</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E5%87%BD%E6%95%B0%EF%BC%88%E4%B8%8B%EF%BC%89.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>函数（下）</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E6%95%B0%E7%BB%84.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>数组</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/%E5%AD%97%E7%AC%A6%E4%B8%B2%E7%9A%84%E6%93%8D%E4%BD%9C.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>字符串的操作</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/Math%E5%92%8CDate.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>Math和Date</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/BOM%E5%92%8CDOM%EF%BC%88%E4%B8%8A%EF%BC%89.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>BOM和DOM（上）</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/js/DOM%EF%BC%88%E4%B8%8B%EF%BC%89.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>DOM（下）</span><!--]--><!----></a><!----><!--]--><!--]--></div></section></div><div class="group" data-v-a186aa16><section class="VPSidebarGroup collapsible" data-v-a186aa16 data-v-6e45c352><div class="title" role="button" data-v-6e45c352><h2 class="title-text" data-v-6e45c352>千锋线下学习</h2><div class="action" data-v-6e45c352><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewbox="0 0 24 24" class="icon minus" data-v-6e45c352><path d="M19,2H5C3.3,2,2,3.3,2,5v14c0,1.7,1.3,3,3,3h14c1.7,0,3-1.3,3-3V5C22,3.3,20.7,2,19,2zM20,19c0,0.6-0.4,1-1,1H5c-0.6,0-1-0.4-1-1V5c0-0.6,0.4-1,1-1h14c0.6,0,1,0.4,1,1V19z"></path><path d="M16,11H8c-0.6,0-1,0.4-1,1s0.4,1,1,1h8c0.6,0,1-0.4,1-1S16.6,11,16,11z"></path></svg><svg version="1.1" xmlns="http://www.w3.org/2000/svg" viewbox="0 0 24 24" class="icon plus" data-v-6e45c352><path 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href="/docs/frontend/qf/JS%E5%87%BD%E6%95%B0.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS函数</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/qf/JS%E5%AF%B9%E8%B1%A1.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS对象</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/qf/JS%E6%95%B0%E7%BB%84%E9%87%8D%E6%9E%84.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS数组重构</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/qf/JS%E6%95%B0%E7%BB%84%E9%87%8D%E6%9E%842.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS数组重构2</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/qf/JS%E8%B7%AF%E7%94%B1.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS路由</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link" href="/docs/frontend/qf/JSDOM.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JSDOM知识</span><!--]--><!----></a><!----><!--]--><!--[--><a class="VPLink link link active" href="/docs/frontend/qf/JS%E4%BA%8B%E4%BB%B6.html" style="padding-left:0px;" tabindex="-1" data-v-70e2cdfb data-v-3c355974><!--[--><span class="link-text" data-v-70e2cdfb>JS事件</span><!--]--><!----></a><!----><!--]--><!--]--></div></section></div><!--]--><!--[--><!--]--></nav></aside><div class="VPContent has-sidebar" id="VPContent" data-v-5211c0b1 data-v-296cfad2><div class="VPDoc has-sidebar has-aside" data-v-296cfad2 data-v-cfb513e0><div class="container" data-v-cfb513e0><div class="aside" data-v-cfb513e0><div class="aside-curtain" data-v-cfb513e0></div><div class="aside-container" data-v-cfb513e0><div class="aside-content" data-v-cfb513e0><div class="VPDocAside" data-v-cfb513e0 data-v-afc4c1a1><!--[--><!--]--><!--[--><!--]--><div class="VPDocAsideOutline" data-v-afc4c1a1 data-v-2865c0b0><div class="content" data-v-2865c0b0><div class="outline-marker" data-v-2865c0b0></div><div class="outline-title" data-v-2865c0b0>On this page</div><nav aria-labelledby="doc-outline-aria-label" data-v-2865c0b0><span class="visually-hidden" id="doc-outline-aria-label" data-v-2865c0b0> Table of Contents for current page </span><ul class="root" data-v-2865c0b0 data-v-1188541a><!--[--><!--]--></ul></nav></div></div><!--[--><!--]--><div class="spacer" data-v-afc4c1a1></div><!--[--><!--]--><!----><!--[--><!--]--><!--[--><!--]--></div></div></div></div><div class="content" data-v-cfb513e0><div class="content-container" data-v-cfb513e0><!--[--><!--]--><main class="main" data-v-cfb513e0><div style="position:relative;" class="vp-doc _docs_frontend_qf_JS%E4%BA%8B%E4%BB%B6" data-v-cfb513e0><div><h3 id="事件基础" tabindex="-1">事件基础 <a class="header-anchor" href="#事件基础" aria-hidden="true">#</a></h3><h4 id="事件的侦听和抛发" tabindex="-1">事件的侦听和抛发 <a class="header-anchor" href="#事件的侦听和抛发" aria-hidden="true">#</a></h4><ul><li>继承EventTarget类型的实例化对象都可以侦听事件</li><li>事件侦听的语法 <code> addEventListener(type, listener);</code></li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// 创建类型</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> target </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">new</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">EventTarget</span><span style="color:#A6ACCD;">()  </span><span style="color:#676E95;font-style:italic;">// 创建一个新的target对象</span></span>
<span class="line"><span style="color:#A6ACCD;">target</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">addEventListener</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">nihao</span><span style="color:#89DDFF;">&#39;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;"> nihaoHandler)  </span><span style="color:#676E95;font-style:italic;">// 给新的对象注册事件监听,并触发监听函数</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> evt </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">new</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">Event</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">nihao</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">evt</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">a </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#F78C6C;">10</span></span>
<span class="line"><span style="color:#A6ACCD;">target</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">dispatchEvent</span><span style="color:#A6ACCD;">(evt)</span></span>
<span class="line"></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">nihaoHandler</span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">e</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">e</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span><span style="color:#F07178;"> </span><span style="color:#676E95;font-style:italic;">// Event</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br></div></div><blockquote><ul><li>事件有侦听有抛发</li><li>事件侦听对象和抛发对象一致</li><li>对象的抛发类型必须和事件的侦听类型一致</li><li>事件必须先侦听后抛发</li></ul></blockquote><h4 id="耦合度" tabindex="-1">耦合度 <a class="header-anchor" href="#耦合度" aria-hidden="true">#</a></h4><ul><li>代码必须解耦,简单来说就是让两个代码之间没有直接联系,互相调用,并且处理数据</li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#676E95;font-style:italic;">// 事例</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> obj1 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;">    </span><span style="color:#F07178;">n</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#F78C6C;">1</span><span style="color:#89DDFF;">,</span></span>
<span class="line"><span style="color:#A6ACCD;">    </span><span style="color:#82AAFF;">a</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">obj2</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">c</span><span style="color:#F07178;">(</span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">a</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">},</span></span>
<span class="line"><span style="color:#A6ACCD;">    </span><span style="color:#82AAFF;">b</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">m</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">m</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">// function () {</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">//      obj2.c(this.a)</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">// }10</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> obj2 </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#A6ACCD;">    </span><span style="color:#82AAFF;">c</span><span style="color:#89DDFF;">:</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">(</span><span style="color:#A6ACCD;font-style:italic;">n</span><span style="color:#89DDFF;">)</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">n</span><span style="color:#F07178;">)</span><span style="color:#89DDFF;">;</span><span style="color:#F07178;"> </span><span style="color:#676E95;font-style:italic;">// 函数体</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">// ƒ () {</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">//      obj2.c(this.a)</span></span>
<span class="line"><span style="color:#89DDFF;">        </span><span style="color:#676E95;font-style:italic;">// }</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">obj1</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">b</span><span style="color:#F07178;">(</span><span style="color:#A6ACCD;">n</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">+</span><span style="color:#F07178;"> </span><span style="color:#F78C6C;">10</span><span style="color:#F07178;">)</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#A6ACCD;">obj1</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">a</span><span style="color:#A6ACCD;">()</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br><span class="line-number">19</span><br><span class="line-number">20</span><br><span class="line-number">21</span><br><span class="line-number">22</span><br><span class="line-number">23</span><br></div></div><h4 id="document" tabindex="-1">document <a class="header-anchor" href="#document" aria-hidden="true">#</a></h4><ul><li>发布模式</li><li>订阅模式</li><li>观察者模式</li></ul><h3 id="事件原理" tabindex="-1">事件原理 <a class="header-anchor" href="#事件原理" aria-hidden="true">#</a></h3><p>事件在侦听过程中经历了3个阶段的触发</p><ul><li>捕获阶段 从外向内</li><li>冒泡阶段 从内向外 addeventListener默认冒泡阶段触发</li><li>目标阶段 就是事件的目标</li></ul><h4 id="系统事件" tabindex="-1">系统事件 <a class="header-anchor" href="#系统事件" aria-hidden="true">#</a></h4><ul><li><p>激活系统抛发事件</p></li><li><p>侦听对象.addEventListener(type,handler,<strong>是否捕获阶段触发<code>[布尔类型]</code></strong>|<strong>{是否捕获阶段触发<code>[对象类型]</code>,是否只监听一次就销毁</strong>})</p></li><li><p>侦听对象.addEventListener(type,handler,{once:true})</p><ul><li><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">div</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">addEventListener</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">click</span><span style="color:#89DDFF;">&quot;</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;">clickHandler1</span><span style="color:#89DDFF;">,</span><span style="color:#FF9CAC;">true</span><span style="color:#89DDFF;">/</span><span style="color:#FF9CAC;">false</span><span style="color:#A6ACCD;">) </span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div></li></ul></li><li><p>侦听对象.removeEventListener(type,handler) <code>删除对象</code> <strong>侦听对象必须与删除侦听对象一致,侦听回调函数必须与删除的侦听回调函数一致,这些引用关系必须相同</strong></p></li></ul><blockquote><ul><li>只有在父子容器中才会出现侦听目标和触发目标不一致</li></ul></blockquote><h4 id="事件委托" tabindex="-1">事件委托 <a class="header-anchor" href="#事件委托" aria-hidden="true">#</a></h4><ul><li>概念 <ul><li>事件产生包容关系的冒泡行为，如果给父容器、子容器都侦听了事件，这时候当触发任意一个元素时，整个父子容器都会收到事件</li><li>如果只针对父容器侦听了事件，子容器没有侦听事件，子容器被事件触发时，将会把事件传递给父元素，父元素收到子元素被触发事件</li></ul></li></ul><h4 id="自定义事件" tabindex="-1">自定义事件 <a class="header-anchor" href="#自定义事件" aria-hidden="true">#</a></h4><h4 id="目标" tabindex="-1">目标 <a class="header-anchor" href="#目标" aria-hidden="true">#</a></h4><ul><li><p>触发目标 e.target e.srcElement</p></li><li><p>侦听目标 this e.currentTarget</p></li><li><p>停止冒泡 e.stopPropagation()</p><ul><li>子容器向父容器传递</li></ul></li><li><p>阻止默认行为 e.preventDefalut()</p><blockquote><p><strong>阻止默认行为举例</strong>:</p><ol><li>右键表单</li><li>表单提交 默认点击submit按钮时会提交到acticon属性的地址中</li><li>reset按钮 表单默认会重置</li><li>图片拖拽 默认拖拽时会产生禁拖标志</li><li>容器中的文字 默认在拖拽时会自动选择文字内容</li></ol></blockquote><p>​</p></li><li><p>阻止同目标事件的后续函数执行 e.stopImmediatePropagation()</p></li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">如果父子元素之间都存在冒泡</span><span style="color:#89DDFF;">,</span><span style="color:#A6ACCD;">那么我们就要使用停止冒泡</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><h3 id="样式的获取" tabindex="-1">样式的获取 <a class="header-anchor" href="#样式的获取" aria-hidden="true">#</a></h3><ul><li>计算后的样式</li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">getComputedStyle</span><span style="color:#A6ACCD;">(div)</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">width)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">   </span><span style="color:#676E95;font-style:italic;">// 指的是所对应的div宽度</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><ul><li>IE浏览器</li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(div</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">currentStyle</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">width)</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><ul><li>offset</li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(div</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">offsetLeft)</span><span style="color:#89DDFF;">;</span><span style="color:#A6ACCD;">    </span><span style="color:#676E95;font-style:italic;">// 返回当前元素左上角节点的左边界偏移的像素值。</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br></div></div><ul><li>获取元素相对视口的矩形区域</li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> div </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> document</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">querySelector</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">.div1</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">getComputedStyle</span><span style="color:#A6ACCD;">(div)</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">width)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br></div></div><h3 id="三种事件的比较" tabindex="-1">三种事件的比较 <a class="header-anchor" href="#三种事件的比较" aria-hidden="true">#</a></h3><ul><li><p>onclick事件只能执行最后一个函数</p><ul><li>阻止冒泡 <ul><li>stopPropagation</li><li>cancelBubble=true IE浏览器兼容</li></ul></li><li>阻止默认行为 <ul><li>e.preventDefault()</li><li>e.returnValue=true IE浏览器兼容</li></ul></li><li>删除onClick事件 <ul><li>XX.onClick = null</li></ul></li></ul></li><li><p>回调地狱</p></li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> bns </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> document</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">querySelectorAll</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">button</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">bns[</span><span style="color:#F78C6C;">0</span><span style="color:#A6ACCD;">]</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">onclick</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> </span><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">bns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">1</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">function</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#A6ACCD;">bns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">2</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">function</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">            </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">            </span><span style="color:#A6ACCD;">bns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">3</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#C792EA;">function</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">()</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">                </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">            </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">        </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br></div></div><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"></span>
<span class="line"><span style="color:#C792EA;">var</span><span style="color:#A6ACCD;"> btns </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> document</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">querySelectorAll</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">button</span><span style="color:#89DDFF;">&#39;</span><span style="color:#A6ACCD;">)</span></span>
<span class="line"><span style="color:#A6ACCD;">btns[</span><span style="color:#F78C6C;">0</span><span style="color:#A6ACCD;">]</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">onclick </span><span style="color:#89DDFF;">=</span><span style="color:#A6ACCD;"> clickHandler1</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">clickHandler1</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了 </span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">btns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">1</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">clickHandler2</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">clickHandler2</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了 </span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">btns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">2</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">clickHandler3</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">clickHandler3</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">已经被点击了 </span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#A6ACCD;">btns</span><span style="color:#F07178;">[</span><span style="color:#F78C6C;">3</span><span style="color:#F07178;">]</span><span style="color:#89DDFF;">.</span><span style="color:#A6ACCD;">onclick</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#A6ACCD;">clickHandler4</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"><span style="color:#C792EA;">function</span><span style="color:#A6ACCD;"> </span><span style="color:#82AAFF;">clickHandler4</span><span style="color:#89DDFF;">()</span><span style="color:#A6ACCD;"> </span><span style="color:#89DDFF;">{</span></span>
<span class="line"><span style="color:#F07178;">    </span><span style="color:#89DDFF;">this.</span><span style="color:#A6ACCD;">textContent</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">=</span><span style="color:#F07178;"> </span><span style="color:#89DDFF;">&#39;</span><span style="color:#C3E88D;">最后一个点击的</span><span style="color:#89DDFF;">&#39;</span></span>
<span class="line"><span style="color:#89DDFF;">}</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br><span class="line-number">4</span><br><span class="line-number">5</span><br><span class="line-number">6</span><br><span class="line-number">7</span><br><span class="line-number">8</span><br><span class="line-number">9</span><br><span class="line-number">10</span><br><span class="line-number">11</span><br><span class="line-number">12</span><br><span class="line-number">13</span><br><span class="line-number">14</span><br><span class="line-number">15</span><br><span class="line-number">16</span><br><span class="line-number">17</span><br><span class="line-number">18</span><br></div></div><ul><li>映射eval --- 不要使用 <ul><li>函数会将传入的字符串当做 JavaScript 代码进行执行。</li></ul></li></ul><div class="language-js line-numbers-mode"><button title="Copy Code" class="copy"></button><span class="lang">js</span><pre class="shiki material-palenight"><code><span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">eval</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">3+4</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">))</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">clickHandler()</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">)</span><span style="color:#89DDFF;">;</span></span>
<span class="line"><span style="color:#A6ACCD;">console</span><span style="color:#89DDFF;">.</span><span style="color:#82AAFF;">log</span><span style="color:#A6ACCD;">(</span><span style="color:#82AAFF;">eval</span><span style="color:#A6ACCD;">(</span><span style="color:#89DDFF;">&quot;</span><span style="color:#C3E88D;">clickHandler()</span><span style="color:#89DDFF;">&quot;</span><span style="color:#A6ACCD;">))</span></span>
<span class="line"></span></code></pre><div class="line-numbers-wrapper" aria-hidden="true"><span class="line-number">1</span><br><span class="line-number">2</span><br><span class="line-number">3</span><br></div></div><ul><li>attachEvent兼容 IE6-8</li></ul><h3 id="event对象" tabindex="-1">EVENT对象 <a class="header-anchor" href="#event对象" aria-hidden="true">#</a></h3><h4 id="系统事件-1" tabindex="-1">系统事件 <a class="header-anchor" href="#系统事件-1" aria-hidden="true">#</a></h4><ul><li>change <ul><li>当输入完成后,和源value值不同时,失焦触发</li></ul></li><li>submit <ul><li>按钮是没有submit事件,这个只针对form表单</li></ul></li><li>reset <ul><li>也是针对于from表单</li></ul></li><li>scroll <ul><li>滚动条</li></ul></li><li>resize <ul><li>只针对window</li></ul></li><li>load</li><li>unload</li><li>select <ul><li>文本框中的文字被选中时触发,包括input/textAear</li><li>input.selectionEnd 返回的是选中个数的开始到结束</li><li>input.setSelectionRange(0,5) 默认选中的input中文本的范围</li></ul></li></ul></div></div></main><!--[--><!--]--><footer class="VPDocFooter" data-v-cfb513e0 data-v-21f75714><!----><div class="prev-next" data-v-21f75714><div class="pager" data-v-21f75714><a class="pager-link prev" href="/docs/frontend/qf/JSDOM.html" data-v-21f75714><span class="desc" data-v-21f75714>Previous page</span><span class="title" data-v-21f75714>JSDOM知识</span></a></div><div class="has-prev pager" data-v-21f75714><!----></div></div></footer><!--[--><!--]--></div></div></div></div></div><footer class="VPFooter has-sidebar" data-v-5211c0b1 data-v-9f24cc86><div class="container" data-v-9f24cc86><p class="message" data-v-9f24cc86>Released under the MIT License.</p><p class="copyright" data-v-9f24cc86>Copyright © 2019-present Evan You</p></div></footer><!--[--><!--]--></div></div>
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